The wireless sensor network consists of many wireless sensor nodes in a particular area. These wireless sensor nodes can sense their surroundings or monitor particular events, and have wireless communication ability. After sampling sensor information, the wireless sensor nodes transmit the sensor information to a data gathering node in a single hop way or in a multi-hop way. The data gathering node can store the sensor information for local use or upload the sensor information to other internet networks. Since the end of 20th century, the wireless sensor network has been improved rapidly and applied in many fields such as military affairs, transportation and environment monitoring, which greatly affects people's living and working.
With the development of the wireless sensor network, it faces a lot of practical problems, the most serious one of which is the limited energy of the wireless sensor nodes. Such a problem is caused by following factors: 1) the wireless sensor node is generally powered by a battery which has limited energy; 2) the wireless sensor nodes are generally disposed in areas which is difficult for human to reach, and thus it is difficult to replace batteries; 3) the number of wireless sensor nodes in the wireless sensor network is large, and thus it wastes lots of manpower to replace the batteries.
The high energy devices such as laptops and mobile phones have more abundant energy than the wireless sensor nodes. When the wireless sensor nodes and the high energy devices exist in the same area, it is possible for the high energy devices to participate in the wireless sensor network, to coordinate interactive operations between the wireless sensor nodes, and to assist the wireless sensor network, thus saving energy. However, in real cases, there are always many high energy devices in one area, and when all the high energy devices coordinate the interactive operations between the wireless sensor nodes simultaneously, the wireless sensor nodes may suffer from behavioral disorders, thus breaking down the wireless sensor network.